1. Field of the Invention
The present invention relates to an attachment fastener.
2. Description of the Related Art
A wide variety of attachment fasteners are currently used for mounting an element, for instance a panel, a tube or cables on a support, such as a plate or the door of a machine or a motorized land vehicle, while ensuring a sealed mounting. The mounting takes place by inserting the attachment fastener through two orifices drilled respectively in the panel and the support. These orifices represent also openings through which elements can be introduced which are undesirable for proper functioning of the machine. These undesirable elements can be for instance dust or, which is a bigger problem, water or any other liquid. Indeed, the presence of water in mechanisms or machines can lead to phenomena of corrosion and premature wear, electrical connectivity problems, etc.
Patent EP-1895171 discloses such an attachment fastener equipped with a head suitable to be mounted on a panel through an orifice of the panel, a leg suitable to be mounted on the support through an orifice of the support, a collar arranged at the junction of the leg and the head, and a sealing washer made of relatively soft plastic material moulded on the periphery of the collar to ensure sealing with the support. The washer is formed in such manner as to have two peripheral lips on its lower side, the internal lip extends axially from the lower side of the washer over a distance smaller than that of the external lip, in order to accommodate different support thicknesses between the leg and the head of the attachment fastener. This type of attachment fastener raises a problem due to the chemical or mechanical interaction between the washer and the attachment fastener which must be controlled very often during the industrial fabrication of the fastener.
Patent US-2006099051 describes another attachment fastener, similar to the one described above, in which the washer is made of supple material and added to the collar. The washer is of simple form with a fine and unique contact point with the support.